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    <title>Help On LaTeX \stackrel and \mathop</title>
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<h3>Hypertext Help with LaTeX</h3>

<h2>\stackrel</h2>

<p>This can be used to stack something above something else;
    used in math mode.</p>

<pre>
  <tt>\stackrel{top}{bot}</tt>
</pre>

<p>The first argument, <tt>top</tt>, is typset immediately above
    the second argument, <tt>bot</tt>; the former is set in the same
    math style as a superscript.</p>

<p>For example</p>

<pre>
  <tt>H$_2$CO$_3$ $\stackrel{<a href="ltx-304.html">\rm</a> heat}
      {<a href="ltx-406.html">\longrightarrow}</a>$ H$_2$O + CO$_2$</tt>
</pre>

<p>will produce something like</p>

<pre><tt>
    heat
    H CO ------> H O + CO
    2 3 2 2
</tt></pre>

<p>Note that the the <tt><a href="ltx-304.html">\rm</a></tt>
    declaration is used so that "heat" is set in Roman face and not
    math italics.</p>

<h2><a name="mathop">\mathop</a></h2>

<p>This command does not seem to be well documented but appears
    to work, at least in current versions of LaTeX 2.09.</p>

<p>The argument is considered to be a single
    <a href="ltx-408.html">variable sized math symbol</a> for
    purposes of placing limits below
    (<a href="ltx-179.html">subscripts</a>) and above
    (<a href="ltx-180.html">superscripts</a>) in
    <a href="mathfonts.html">display math</a> style. For example,</p>

<pre>
  <tt>\mathop{\sum \sum}_{i,j=1}^{N} a_i a_j</tt>
</pre>

<p>would produce something like</p>

<pre>
            N
         ---  ---
         \    \    
         /    /    a  a
         ---  ---   i  j
           i,j
</pre>

<p>It is possible to create <strong>two rows</strong> of
    "subscripts" by using a similar construction: The first row is
    created as subscripts of the symbol in the usual way and a lower
    row is created by placing this whole construct as the argument
    of a <tt>\mathop</tt> command with its own subscript. For example</p>

<pre>
  <tt>\mathop{\sum_{i,j=1}^{N}}_{i&gt;j}</tt>
</pre>

<p>would produce something like</p>

<pre>
          N
         ---  
         \        
         /    
         ---  
         i,j=1
         i&gt;j
</pre>

<hr noshade="noshade" size="1">

<p>Related topics</p>

<ul>
    <li><a href="ltx-115.html">Math Formulas</a>
        and <a href="ltx-117.html">Math Symbols</a></li>
    <li><a href="ltx-406.html">Arrows</a></li>
    <li><a href="ltx-404.html">Binary and relational opertors</a></li>
    <li><a href="ltx-223.html">Eqnarray Environment</a></li>
    <li><a href="ltx-224.html">Equation Environment</a></li>
    <li><a href="ltx-421.html">Displaymath Environment</a></li>
    <li><a href="mathfonts.html">Math Fonts and Styles</a></li>
</ul>

<ul>
    <li><tt><a href="ltx-287.html">\overbrace</a></tt></li>
    <li><tt><a href="ltx-288.html">\overline</a></tt></li>
    <li><tt><a href="ltx-335.html">\underbrace</a></tt></li>
    <li><tt><a href="ltx-336.html">\underline</a></tt></li>
</ul>

<p>
    Return to <a href="ltx-2.html">LaTeX Table of Contents</a>
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<address>
    Revised 15 Aug 1995.
</address>
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